Lap grinding machine



Oct. 2.2,v 1957- Filed' Deo. 22, 1,954

P. J. SOMMER, JR 2,810,237

LAP GRINDING'MACHINE 2 Sheets-Sheet 1 Oct. 22, 1957 P. J. SOMMER, JR

LAP GRINDING MACHINE 2 Sheets-Sheet 2 Filed Dec, 22. m54

INVENToR. eer Jam/werd;

nite States Patent 2,810,237 Patented Oct. 22, 1957 ffice LAP GRINDING MACHINE Peter J. Sommer, Jr., Lombard, lll., assignor to Size Control Company, a division of American Machine d; Gauge Company, Chicago, Ill., a copartnership Application December 22, 1954, Serial No. 476,881

4 Claims. (Cl. 51-103) This invention has to do with precision machine tools, having particular reference to a centerless lap grinding machine provided with a control device, whereby the lap pressure roller and the lap grinding roller can be spaced apart to operate in pre-determined parallel planes, as well as angularly with respect to each other, to provide novel and advantageous results not heretofore attained, and the provision of such a device, and method for precision finishing work-pieces, is a principal object of the invention.

Generally, it is an object of the invention to provide an improved control device for the type of lapping machine disclosed in my U. S. Patent No. 2,465,178.

More specifically, it is an object of the invention to provide, in a centerless lap grinding machine for precision finishing cylindrical work-pieces, having a lap grinding roller journaled in iixed position and a lap pressure roller journaled in movable position, an improved Vcontrol device comprising means to move the pressure roller in a parallel plane in spaced relation to the plane of the grinding roller, and means to tilt the pressure roller in an angular plane with respect to the grinding roller, whereby the work-pieces can be ground between the parallel spaced and angularly tilted rollers.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the device embodying features of construction, combination of elements and arrangement of parts which are adapted to effect such steps, all as exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understandingof the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawings, in which: y k

Fig. 1 is a side elevational View of the device embodying the invention;

Fig. 2 is a plan view of Fig. 1; A

, Fig. 3 is a transverse sectional View, taken along the lines 3*-3 of Fig. 1 and looking in the direction of the arrows; and I Fig. 4 is a perspective View of the device embodying the invention.

Referring more particularly to the drawings, there is indicated generally at a control device embodied by the invention, illustrated as being mounted upon a `standard or frame 11 of the type disclosed in my above mentioned patent.

The present device is mounted in a separate frame-work 12, secured to the frame 11, at the rear end of which frame-work are mounted spaced-apart standards 13 secured in iixed position by bolts 14. At the vtop of each standard is a bearing l15 in which is journaled a shaft 16 carrying a lap grinding roller`17. Thisvroller is driven by means of a belt from a countershaft connected to a source of power as disclosed in said patent.

Mounted in advance of the lap grinding roller is a lap pressure roller 18, also as set forth in the patent. These rollers are of different diameters, rotating in the same direction, but at different speeds, and the manner in which this is accomplished needs no further amplification. However, the manner of rotating, regulating and controlling the lap pressure roller is somewhat different, forming part of the present invention, and will more fully be described hereinafter.

The lap pressure roller 18 has a shaft 19 therethrough and this is journaled in bearings 20 of a bearing yoke 21 which extends transversely across the top of the machine. At opposite ends of the yoke underneath the bearings aredepending arms 22 pivotally mounted therein by pivot pins 23. These arms are slidably mounted in a bearing yoke support 24 so that the lap pressure roller can be angularly tilted. This may be accomplished by means of a hand wheel 25 having a graduated collar 26 extending from the front of the frame 12 and having a fluted shaft 27 extending through the frame at this point. The iluted shaft is slidably mounted in a splined sleeve 28, the end of which is connected to an upstanding lug 29 centrally of the rear of the yoke bearing support 24 and connected to the yoke bearing Z1.

Directly underneath the hand Wheel 25 is another hand wheel 30 also having a graduated collar 31. This hand wheel is connected to an elongated screw thread 32 which is screw-threaded through the center of the yoke bearing support 24 and secured to the standard 13 as at 33.

The yoke bearing support 24 is slidably mounted at opposite ends on slide bars 34 secured in bearing mounts 35 on the frame-work 12.

The rotation of the lap pressure roller 18 and its speed of rotation is controlled by a belt 36 coming off the countershaft (not shown) from which the lap grinding roller 17 derives its rotation, preferably in the manner disclosed in my above mentioned patent. The belt 35 passes around a pulley 37 secured to a shaft 38 which is mounted in a bearing 38 on the frame-work 12. Also attached to the shaft 38 is a pulley 39, as well as an upstanding fork-link 40, pivotally mounted on the shaft 38. At the top of the fork-link 46 is a pivot pin 41 carrying two pulleys 42 and 42 as well as an elongated fork-link 43. This latter fork-link also has a pivot pin 44 carrying two pulleys 45 and 45 as well as a third but shorter fork-link 46, which in turn is pivotally connected to the end of the shaft 19 on which the lap pressure roller 18 is mounted. A pulley 47 is also keyed to the shaft 19.

A series of belts transmit rotation to the lap pressure roller 18 from the pulley 37. The iirst of these belts 4S passes around the pulleys 39 and 42. The second of these belts 49 passes around pulley 42' and 4S. The third belt 50 passes around pulleys 45 and 47. By this driving arrangement it will be seen that the lap pressure roller 18 can be moved horizontally as well as vertically without causing any slack in the belts and consequent loss of speed of rotation.

In operation, the hand lwheel 30 is turned to move the lap pressure roller in parallel spaced relation with respect to the lap grinding roller 17. Heretofore, it was customary to space these rollers closely adjacent each other. However, in Vaccordance with the principles of the present invention, I space the rollers 17 and 18 a substantial distance apart, that is, a distance which is slightly le'ss than the diameter of the cylindrical workpiece 51, in a manner such that the center or longitudinal axis thereof lies slightly above the plane of the longitudinal :axes of the rollers 17 and 18. The spacing of the rollers 17 and 181, ofcourse, is accomplished by sliding the yoke bearing support 24 along the slide bars 34, simply by turning the hand wheel in a manner such that the plane through `the axes of the rollers 17 and 18 remain parallel.` Withthis unconventional spacing apartof; these rollers the bight formed therebetween is considerably differentthan used heretofore and apparently increases the pressure and traction angles whereby a considerably greater amount of stock can be removed in much less time and permits the finishing of larger work-pieces, thereby greatly increasing the range of the machine.

When the desired position of the rollers 17 and 18 is obtained, the bearing yoke support 24 is locked in such position by means of the knurled hand wheels 52 threadedly mounted in the ends thereof and adapted to engage the slide bars 34.

The efiicacy of thedevice is Ifurther enhanced `to produce additional new results, such as good straight pieces, better finish, and the ability automatically to cause the work-pieces to pass transversely along the bight of the rollers. Heretofore, it was necessary for an operator to hold a pressure stick against the `workapiece and work it along the bight of the rollers. Now, this latter operation is eliminated by the spacingof the rollers because of the added pressure angle and traction that is obtained. However, in order to obtain these latter new results and to cause work-pieces to automatically travel along the bight of the rollers, I tilt the lap pressure roller along its vertical plane. The means whereby I accomplish this is the hand wheel 25, fluted shaft 27 and splined sleeve 28 arrangement. In other words, after the bearing yoke support 24 has been locked in position by the knurled members 52, turning of the hand wheel 25 will properly tilt the lap pressure roller 18 in a trnanner such that the longitudinal axis thereof is at an angle with respect to the longitudinal axis oufV the lap grinding roller 17, although these rollers still remain in spaced parallel planular relationship. This angular tilting is depicted in Fig. 3 but in a highly exaggerated form for illustrative purposes. only be a small fraction of an inch-even in thousandths of an inch. When the desired angle is obtained the lap pressure roller 18 is locked in this portion by means of knurled set screws 53 threadedly entering opposite ends of the yoke bearing 21 and engaging the slidably mounted arms 22. Such tilting causes the work-pieces slowly to run to the high side of the lap pressure roller 18, providing a much better finish and straighter pieces'than heretofore.

It is also within the contemplation of the invention angularly to tilt the lap pressure roller 18 by raising either one end, or the other end, while the opposite end remains fixed, rat-her than tilting-it from a. center point, whereby `one end is lowered as the other end is raised as shown in Fig. 4 of the drawing.

This is accomplished by making the bearings 20 slidably or reciprocably mountable in the bearing yoke 21. Each bearing 20 had a downwardly extending anni 55 having teeth 56 as on a rack bar. A pinion 57 engages the teeth 56 `and has a stud shaft 58 extending through the side of the yoke housing portion 59 which is hollow to house the bearing arm 55. At each end of the shaft 58 is a graduated hand wheel 60 selectively to tilt one or the other end of the lap pressure roller 18. When the desired angularity of the roller 18 is obtained, the same is locked in position by the knurled hand wheel 61 on the screw-threaded stud 62 passing through the housing portion 59 of the bearing yoke 24 to engage and lock the bearing arm 55.

It will thus `be seen that the objects and new results heretofore set forth may readily and efliciently be attained by means of the present invention.

Since certain changes in carrying out the above process and in the construction set forth, which embody the invention may be made without departing from its scope,

It :should be understood that such tilting might e 4 it is intended that all mattercontained in the above de scription or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to Lbe understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a centerless lap grinding cmachine, for precision finishing cylindrical work-pieces, having a lap grinding roller journaled in fixed position and a lap pressure roller of different diameter, rotating in the same direction but at different speed, journaled in movable position, the improvement comprising `in combination; means to move said pressure roller in parallel spaced relation to said grinding roller; means including a U-shaped bearing yoke extending underneath and longitudinally of said pressure roller and terminating in bearings for said pressure roller, a depending arm slidably mounted in a yoke support and pivotally mounting said yoke at its end, a uted member connected normally in the center of said yoke, and a uted shaft passing therethrough and mounted to rotate in a bearing on said yoke support, to tilt said pressure roller in an angular plane with respect to said grinding roller; and driving means, including a fork linkage, connected to said pressure roller and cooperatively movable therewith while the same is in said parallel and angular position; whereby said work-pieces can be ground between said parallel spaced and angularly tilted rollers.

2. In a centerless lap grinding machine, for precision finishing cylindrical work-pieces, having a lap grinding roller journaled in fixed position and a lap pressure roller of different diameter, rotating in the same direction but at different speed, journaled in movable position, the improvement comprising in combination; means to move said pressure roller in parallel spaced relation to said grindingY roller; means, including a U-shaped bearing yoke extending underneath and langitudinally of said pressure roller and terminating in bearings for said pressure roller, a depending arm slidably mounted in a yoke support and pivotally mounting said yoke at its end, a fluted member connected `normally in the center of said yoke, and a uted shaft passing therethrough and mounted to rotate in a bearing on said yoke support to tilt said pressure roller in an angular plane with respect to said grinding roller; and driving means, including a pivotally connected forklinkage having driving pulleys pivotally connected thereto, mounting driving belts, at their pivot points, connected to said pressure roller and cooperatively movable therewith while said pressure roller is in said parallel and angular position; whereby said work-pieces can be ground between said parallel spaced and angularly tilted rollers.

3. In a centerless lap grinding machine, for precision finishing cylindrical work-pieces, having a lap grinding roller journaled in fixed position and a lap pressure roller of different diameter, rotating in the same direction but at different speed, journaled in movable position, the improvement comprising in combination; means, including a. bearing yoke support to move said pressure roller in parallel spaced relation to said grinding roller; means, including a U- shaped bearing yoke, extending underneath and longitudinally of said pressure roller and terminating in bearings for said pressure roller, and a rack and pinion to raise and lower said bearings, mounted on said support to tilt said pressure roller from one end only in an angular plane with respect to said grinding roller; means to tilt both ends of said yoke and pressure roller in opposite directions around the short axis of said yoke in an angular plane with respect to said grinding roller, which tilting means includes a depending arm slidably mounted in a` yoke support and pivotally mounting said yoke at its end, a fluted member connected normally in the center of said yoke, and a uted shaft passing therethrough and mounted to rotate in a bearing on said yoke support and driving means, including a pivotally connected forklinkage having driving pulleys pivotally connected thereto, mounting driving belts, around their pivot points, connected to said pressure roller and cooperatively movable therewith while said pressure roller is in said parallel and angular position; whereby said work-pieces can be ground between said parallel spaced and angularly tilted rollers.

4. In a centerless lap grinding machine for precision finishing of cylindrical workpieces, having a lap grinding roller journaled in lixed position, and a lap pressure roller of different diameter, rotating in the same direction but at a different speed, journaled in movable position, the improvement comprising in combination; means to move `said pressure roller in parallel spaced relation to said grinding roller; a tiltable bearing yoke extending underneath and longitudinally of said pressure roller and terminating in bearings therefor; means to tilt said yoke and pressure roller in an angular plane with respect to said grinding roller, which tilting means includes a depending arm slidably mounted in a yoke support and pivotally mounting said yoke at its end, a uted member connected normally in the center of said yoke, and a -uted shaft passing therethrough and mounted to rotate in a bearing on said yoke support; and driving means connected to said pressure roller and cooperatively movable therewith while the same is in said parallel and angular position, whereby said work-pieces can be ground between said parallel spaced and angularly tilted rollers;

References Cited in the file of this patent UNITED STATES PATENTS 1,663,759 Ham Mar. 27, 1928 2,073,079 Theler et al. Mar. 9, 1937 2,196,108 Dunbar et a1. Apr. 2, 1940 2,465,178 Sommer, Jr Mar. 22, 1949 2,520,228 Thomte Aug. 29, 1950 

